Tony le Stephanois is released from prison having served five years for refusing to snitch on his best friend, Joe the Swede. The two friends, and associate Mario Farrati, plan to celebrate Tony's freedom the best way they know how: by planning a daring robbery on the most exclusive jewellery store in the whole of Paris. Practice certainly makes perfect as the robbers take their chances, employing expert safe cracker Cesar the Milanese to get them to the loot.